1. Field of the Invention
The present invention relates to a process for two-stage injection molding of an air-conditioning blow-out port device mounted in an instrument panel or the like in an automobile.
2. Description of the Prior Art
There is such a conventionally known blow-out port device comprising a housing which includes pairs of shaft bores provided in a coaxial arrangement in opposed wall portions of a peripheral wall thereof, and pairs of bosses also provided at the opposed wall portions to define openings of the shaft bores inside the opposed wall portions, respectively, and a plurality of blades which each includes a pair of abutment flanges abutting against a pair of the bosses, and a pair of support shafts projectingly provided on surfaces of the abutment flanges and rotatably fitted in the shaft bores. This blow-out port device is produced by a two-stage injection molding process which comprises forming the housing at a primary injection step using synthetic resin and forming the blades by use of the shaft bores as support shaft forming cavities at a secondary injection step.
With the above prior art process, however, a problem is encountered that the bosses of the housing and the abutment flanges of the blades are failed to be formed into a circular section configuration, because the axes of the support shafts are offset from matched surfaces of opening/closing dies. Consequently, if the blades of the blow-out port device produced in the above process is turned in order to adjust the direction of wind, each of the bosses and each of the abutmerit flanges may be offset from each other, in some cases, and a portion of the abutment flange may protrude from the boss, resulting in an inferior appearance.
Thereupon, if the air-conditioning blow-out port device is constructed of a housing which includes pairs of shaft bores provided in a coaxial arrangement in opposed wall portions of a peripheral wall thereof to extend through the opposed wall portions, and pairs of circular-section bosses located coaxially with the shaft bores to define openings of the shaft bores inside the opposed wall portions, respectively, and a plurality of blades which each include a pair of protruding portions abutting against a pair of the bosses and each having the same outside diameter as the boss, and a pair of support shafts projectingly provided coaxially on end faces of the protruding portions and turnably fitted in the shaft bores, respectively, it is possible to overcome the above problem to provide an improved appearance around a mounting portion of each of the blades, because each of the protruding portions and each of the bosses cannot be offset from each other, even if the blades are turned.